Ballistic body armor employing combination of desiccant and ballistic material

ABSTRACT

A ballistic body armor and dehumidification system includes a flexible carrier containing a watertight sealed pouch which itself contains a desiccant and a stack of substantially vertical layers of ballistic material whose performance degrades under certain conditions in the presence of moisture. The watertight sealed pouch is mounted into the carrier so as to cover a portion of a user&#39;s body. The desiccant is mounted or laminated into the pouch so that either it is, or its effect is, distributed across the ballistic material to uniformly reduce the humidity level within the pouch.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/248,975 filed Mar. 6, 2003 entitled Ballistic Body ArmorEmploying Combination of Desiccant and Ballistic Material which claimspriority from U.S. Provisional Patent Application No. 60/362,067 filedMar. 7, 2003 entitled Combination Desiccant and Ballistic Material inBallistic Body Armor.

FIELD OF THE INVENTION

This invention relates to the field of body armor and in particular tothe use of a desiccant in combination with the ballistic material ofbody armor in order to maintain humidity in the body armor beneathperformance reducing levels.

BACKGROUND OF THE INVENTION

P-phenylene-2,6-benzobisoxazole, referred to herein and by onemanufacturer, Toyobo Co., Ltd. of Osaka, Japan, by the acronym PBO andsold by that manufacturer under the trademark Zylon, is advertised as arigid-rod lyotropic liquid crystal polymer having tensile strength andmodulus superior to P-Aramid fibres, and as exhibiting outstanding highflame resistance and thermal stability among organic fibres.

In applicant's experience, use of Zylon™ in ballistic body armor mayprovide up to approximately thirty percent better performance ascompared to, for example, older aramid ballistic materials. Zylon™ isthus now a commonly used ballistic material in body armor design becauseof its improved performance to protect against penetration by ballisticprojectiles such as bullets. However, it is now been identified thatZylon™ degrades under combined high heat and high humidity conditions soas to adversely affect its ballistic performance. The degradation isnot, as far as applicant is aware, the impermanent performancedegradation such as has been previously identified due to moisture inthe use Kevlar™ woven aramid fibre cloth, but rather results inpermanent degradation of the ballistic material performance.

In applicant's experience, and in applicant's prior art designs such assold by Pacific Safety Products of Kelowna, British Columbia, Canada,applicant and other designers of ballistic armor take extreme care inthe design of, and rigorously test, any changes to the order, number andcomposition of the layers of material found with ballistic body armor. Auser's life may depend on it. Consequently, the introduction by a personskilled in the art of flexible ballistic body armor of a substance orlayer into the ballistic material layers which is foreign toconventional substances or layers conventionally found in ballistic bodyarmor is in applicant's experience rarely done. Changes andmodifications are only very conservatively implemented to avoid chancesof unforeseen adverse consequences to the ballistic performance of thelayers of ballistic material whether they be woven aramid fibre layersor the PBO layers which are the subject of the present invention.Applicant's invention is thus unconventional in that at least one layerof a foreign desiccant substance; for example at least one layer ofdesiccant sheet is interleaved, sandwiching, or sandwiched between thelayers of conventional PBO ballistic material in flexible ballistic bodyarmor. It is an object of the present invention to introduce a desiccantinto ballistic body armor employing PBO fibre ballistic body armor so asto inhibit permanent performance degradation of the material's ballisticpenetration resistance due to moisture within the body armor.

In the prior art, applicant is aware of patents disclosing the use ofmoisture control materials in protective clothing for the purposes ofthe comfort of the wearer. In particular, applicant is aware of patentswhich disclose the use of wicking and other materials to transfer,evaporate or absorb moisture within the garment, as for example founddisclosed in U.S. Pat. No. 6,044,498 which issued to Schumann et al. onApr. 4, 2000 for Slash and Cut Resistant Garments for Protecting aPerson From Injury, U.S. Pat. No. 5,471,906 which issued Bachner, Jr. etal. on Dec. 5, 1995 for a Body Armor Cover and Method for Making theSame, U.S. Pat. No. 5,327,811 which issued to Price et al. on Jul. 12,1994 for a Lightweight Ballistic Protective Device, U.S. Pat. No.5,472,769 which issued to Goerz, Jr. et al. on Dec. 5, 1995 for a SoftBody Armor Material with Enhanced Puncture Resistance Comprising atLeast One Continuous Fabric Having Knit Portions and Integrally WovenHinge Portions, U.S. Pat. No. 6,233,737 which issued to Ditchfield etal. on May 22, 2001 for a Concealable Ballistic Vest and U.S. Pat. No.6,138,277 which issued to Gillen et al. on Oct. 31, 2000 for aProtective Body Vest. The moisture control in this prior art generallyinvolves the use of fabric layers for example the moisture absorbinginner layer of Goerz, Jr., or the vapour permeable cover layer over theflexible armor plating layer of Bachner, Jr. et al. Similarly, in theprior art applicant is also aware of a Korean Patent, Patent No. KR2001017116 which issued to Lee for a Bulletproof Vest Having AirVentilation Property and which discloses the use within a bulletproofvest of inner covers of foamed polyethylene material providing such anair ventilation property so that sweat moisture is transferred from thebody of the user to a moisture absorbing fibre positioned inside anouter cover.

SUMMARY OF THE INVENTION

The present invention is ballistic body armor wherein sheets ofballistic material such as PBO or other unidirectional (“UD”), or wovenballistic material are contained in a layered stack within a sealedwatertight pouch mounted or mountable into a flexible carrier for wearby a user. The pouch is sealed so that whatever ambient humidity isintroduced into the pouch during manufacturing remains the maximumambient humidity. A desiccant and desiccant storage means, for exampledesiccant impregnated sheets of paper, are contained within the pouch.The desiccant sheets may form inter-leaved layers within the stack oflayers of ballistic material or may sandwich the stack, or may be asingle sheet which may be sandwiched within the stack or otherwiseinserted anywhere into the pouch. The desiccant removes or reduceshumidity levels within the pouch to such low levels as to remain belowhumidity levels which, in combination with high heat, would permanentlydegrade the performance of PBO fibres making up the layers of ballisticmaterial.

It is intended to be within the scope of the present invention tointroduce desiccant by a storage and delivery means, such as a matrix orsheet impregnated with a desiccant chemical composition, into a sealedpouch containing layers of ballistic material such as PBO whoseballistic performance degrades due to high humidity so as to inhibithigh humidity induced ballistic performance degradation of the ballisticmaterial within the pouch. The pouch is for mounting into ballistic bodyarmor.

In summary then, the ballistic body armor and dehumidification systemaccording to the present invention includes a flexible carrier forwearing by a user. The carrier contains a watertight sealed pouch. Thepouch contains a stack of layers of ballistic material, such as PBO,whose performance degrades under certain conditions in the presence ofmoisture, and a desiccant. The watertight sealed pouch is mounted intothe carrier so as to cover a portion of the user's body when the user iswearing the body armor. When the armor is worn by the user, the stack isa stack of substantially vertical layers of flexible ballistic materialmounted into the pouch. The desiccant is mounted into the pouch.Alternatively, the desiccant is laminated into the pouch. Because of thewicking effect or aerating effect of the ballistic material, thedesiccant may be placed anywhere within the pouch and its effect isdistributed uniformly across the stack, to uniformly reduce a humiditylevel within the pouch and the stack. The desiccant and the nature ofthe ballistic material cooperate so that a small amount, such as a smallsheet of a desiccant impregnated flexible matrix simply placed anywherein the pouch will have a far-reaching dehumidification effect on theconventionally closely compacted stack of layers of ballistic material.

The desiccant sheet may be interleaved between layers of the stack ormay be partially co-extensive with the layers in the pouch, and/orsandwiched between the stack and a wall of the pouch and may bepartially co-extensive with an outermost layer of the stack. Thedesiccant may be a matrix other than a sheet or may be a plurality ofcarrier sheets impregnated with a desiccant means such as a desiccantchemical composition or a sheet containing desiccant formed from aplastic compound having a means integrated directly into the compound,wherein the plurality of sheets are interleaved with or snugly adjacentto, or laminated onto the stack, again, for example, at least partiallyco-extensive with the layers in the stack.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is, in elevation view, the front and back panel of one form ofbody armor incorporating the present invention laid flat, the armorcasing partially cut away.

FIG. 2 is, in partially cut away elevation view, a water imperviouspouch containing sheets of ballistic material and desiccant for mountinginto the body armor of FIG. 1.

FIG. 3 is a sectional view along line 3-3 in FIG. 2.

FIG. 4 is a side view of a sheet containing desiccant laminated betweensheets of ballistic material.

FIG. 5 is a sectional view of a water impervious pouch having sheetscontaining desiccant laminated between sheets of ballistic material formounting into the body armor 5.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

With reference to the drawings, wherein similar characters of referencedenote corresponding parts in each view, as seen in FIGS. 1-5, ballisticbody armor 10 may include front and back panels 12 and 14 respectively.Each of the panels may have an outer fabric casing or carrier 16, forexample sewn around the panel's circumferential edges so as to define incombination with the assembled front and back panels, side arm openingsand an upper neck opening for the user. Within each of the panels, andretained snugly and conformally so as to correspond to the profiledoutline of each panel, is a sealed water impermeable pouch 18, forexample, a heat sealed plastic pouch.

Each pouch is sealed contiguously around its perimeter so as to define acavity 20 within the pouch, as better seen in FIG. 5. The cavity isgenerally planar when the pouch is laid flat. A stack of adjacentlylayered generally parallel sheets of Zylon™ PBO fibre material 22 aresnugly mounted within pouch 18 so as to maintain sheets 22 generallyparallel and compactly sandwiched between front and back faces 18 a and18 b respectively of pouch 18.

Pouch 18 contains at least one flexible sheet 24 impregnated with adesiccant such as Drikette Desiccant Paper, sold by S & D Chemical ofScarborough, Ontario, Canada, and manufactured by Multisorb TechnologiesInc. of Buffalo, N.Y., United States. Such desiccant paper may absorb upto three hundred times its weight in moisture. Sheets 24 may bedesiccant impregnated paper sheets, but it is not intended to belimiting as many desiccant storage and delivery means would work tointroduce the desiccant and uniformly dehumidify a stack of sheets 22within sealed pouch 18 so as to reduce humidity levels within the pouch.For example, in an embodiment of the invention, sheet 24 may be a filmor sheet containing desiccant 24′ formed from a plastic compound havingdesiccant integrated directly into the plastic compound, such as theActiv-pak™ desiccant film and sheet manufactured by CSP TechnologiesInc. of Auburn, Alabama, United States. At least one sheet or film 24′containing desiccant may be laminated or mounted onto sheet 22.Alternatively, sheet or film 24′ containing desiccant may be laminatedbetween sheets 22 such that sheet or film 24′ containing desiccant issandwiched between two sheets of adjacently layered generally parallelballistic material such as Zylon™ PBO fibre material 22, as seen inFIGS. 4 through 5. In the further alternative, sheet or film 24′containing desiccant may be used to laminate unidirectional (“UD”)layers of ballistic fibres to form sheet 22. That is, desiccant may beincorporated directly into sheets of UD ballistic material when thesheets are made, for example by incorporating desiccant into the binderor laminate such as the thermoplastic film that forms the substrate thatbinds the UD layers of ballistic fibres in place to form the sheets. Theuse of desiccant sheets may provide the advantage of a consistent,structurally stable and uniform distribution of the desiccant across,that is parallel to, at least a portion of the surface area of the pouchwhich would be exposed to penetration by ballistic projectiles. Uniformdistribution of the effect of the desiccant, which remains constantlyuniform in cooperation with the wicking or porous nature of theballistic material such as PBO ballistic material offers the advantageof uniform humidity control across the pouch no matter where thedesiccant is mounted, so long as exposed to the ballistic material inthe pouch, which may be relied on for the operative life of the armor,minimizing the risk of isolated areas of higher humidity within thedistributed volume of the cavity within the pouch.

As will be apparent to those skilled in the art in the light of theforegoing disclosure, many alterations and modifications are possible inthe practice of this invention without departing from the spirit orscope thereof. Accordingly, the scope of the invention is to beconstrued in accordance with the substance defined by the followingclaims.

1. Ballistic body armor comprising a flexible carrier for wearing by auser, a watertight sealed pouch mounted into said carrier so as to covera portion of the user's body, a compacted stack of substantiallyvertical layers of flexible ballistic material mounted into said pouch,a desiccant mounted into said pouch wherein said desiccant reduces ahumidity level within said pouch and said compacted stack.
 2. Theballistic body armor of claim 1 wherein said desiccant is at least onedesiccant impregnated sheet.
 3. The ballistic body armor of claim 1wherein said ballistic material is PBO.
 4. The ballistic body armor ofclaim 1 wherein said ballistic material is unidirectional ballisticmaterial.
 5. The ballistic body armor of claim 2 wherein said ballisticmaterial is PBO.
 6. The ballistic body armor of claim 3 wherein saiddesiccant is at least one desiccant impregnated sheet.
 7. The ballisticbody armor of claim 2 wherein said sheet is interleaved between layersof said stack.
 8. The ballistic body armor of claim 6 wherein said sheetis interleaved between layers of said stack.
 9. The ballistic body armorof claim 2 wherein said sheet is sandwiched between said stack and awall of said pouch.
 10. The ballistic body armor of claim 1 wherein saiddesiccant is a plurality of sheets impregnated with a desiccant means,and wherein said plurality of sheets are interleaved with or snuglyadjacent to said stack.
 11. The ballistic body armor of claim 1 whereinsaid plurality of sheets are co-extensive with said layers in saidstack.
 12. Ballistic body armor system for reducing humidity in sealedflexible body armor comprising a flexible carrier for wearing by a user,a watertight sealed pouch mountable into said carrier so as to cover aportion of the user's body, a stack of substantially vertical layers offlexible ballistic material mountable into said pouch, a desiccantmountable into said pouch so as to be distributed within said stack,wherein said desiccant reduces a humidity level within said pouch andsaid stack.
 13. The ballistic body armor of claim 12 wherein saiddesiccant is at least one desiccant impregnated sheet.
 14. The ballisticbody armor of claim 12 wherein said ballistic material is PBO.
 15. Theballistic body armor of claim 12 wherein said ballistic material isunidirectional ballistic material.
 16. The ballistic body armor of claim13 wherein said ballistic material is PBO.
 17. The ballistic body armorof claim 14 wherein said desiccant is at least one desiccant impregnatedsheet.
 18. The ballistic body armor of claim 13 wherein said sheet whenmounted in said stack is interleaved between layers of said stack so asto be co-extensive with said layers in said pouch.
 19. The ballisticbody armor of claim 17 wherein said sheet is interleaved between layersof said stack so as to be co-extensive with said layers in said pouch.20. The ballistic body armor of claim 13 wherein said sheet when mountedin said pouch is sandwiched between said stack and a wall of said pouchand is co-extensive with an outermost layer of said stack.
 21. Theballistic body armor of claim 12 wherein said desiccant is a pluralityof sheets impregnated with a desiccant means, and wherein said pluralityof sheets when mounted in said pouch are interleaved with or snuglyadjacent to said stack.
 22. The ballistic body armor of claim 12 whereinsaid plurality of sheets when mounted in said pouch are co-extensivewith said layers in said stack.
 23. Ballistic body armor comprising aflexible carrier for wearing by a user, a watertight sealed pouchmounted into said carrier so as to cover a portion of the user's body, acompacted stack of substantially vertical layers of flexible ballisticmaterial mounted into said pouch, a desiccant laminated into said pouchwherein said desiccant reduces a humidity level within said pouch andsaid compacted stack.
 24. The ballistic body armor of claim 23 whereinsaid desiccant is at least one desiccant impregnated sheet.
 25. Theballistic body armor of claim 23 wherein said ballistic material is PBO.26. The ballistic body armor of claim 23 wherein said ballistic materialis unidirectional ballistic material.
 27. The ballistic body armor ofclaim 24 wherein said ballistic material is PBO.
 28. The ballistic bodyarmor of claim 25 wherein said desiccant is at least one desiccantimpregnated sheet.
 29. The ballistic body armor of claim 24 wherein saidsheet is interleaved between layers of said stack.
 30. The ballisticbody armor of claim 28 wherein said sheet is interleaved between layersof said stack.
 31. The ballistic body armor of claim 24 wherein saidsheet is sandwiched between said stack and a wall of said pouch.
 32. Theballistic body armor of claim 23 wherein said desiccant is a pluralityof sheets impregnated with a desiccant means, and wherein said pluralityof sheets are interleaved with or snugly adjacent to said stack.
 33. Theballistic body armor of claim 23 wherein said plurality of sheets areco-extensive with said layers in said stack.
 34. The ballistic bodyarmor of claim 23 wherein said desiccant laminates unidirectional layersof ballistic fibres to form said ballistic material.
 35. Ballistic bodyarmor system for reducing humidity in sealed flexible body armorcomprising a flexible carrier for wearing by a user, a watertight sealedpouch mountable into said carrier so as to cover a portion of the user'sbody, a stack of substantially vertical layers of flexible ballisticmaterial mountable into said pouch, a sheet containing desiccantmountable into said pouch so as to be distributed within said stack,wherein said desiccant reduces a humidity level within said pouch andsaid stack.
 36. The ballistic body armor of claim 35 wherein saidballistic material is PBO.
 37. The ballistic body armor of claim 35wherein said ballistic material is unidirectional ballistic material.38. The ballistic body armor of claim 35 wherein said sheet when mountedin said stack is interleaved between layers of said stack so as to beco-extensive with said layers in said pouch.
 39. The ballistic bodyarmor of claim 36 wherein said sheet is interleaved between layers ofsaid stack so as to be co-extensive with said layers in said pouch. 40.The ballistic body armor of claim 36 wherein said sheet when mounted insaid pouch is sandwiched between said stack and a wall of said pouch andis co-extensive with an outermost layer of said stack.
 41. The ballisticbody armor of claim 35 wherein said desiccant is a plurality of sheetsimpregnated with a desiccant means, and wherein said plurality of sheetswhen mounted in said pouch are interleaved with or snugly adjacent tosaid stack.
 42. The ballistic body armor of claim 35 wherein saidplurality of sheets when mounted in said pouch are co-extensive withsaid layers in said stack.
 43. The ballistic body armor of claim 23wherein said desiccant laminates unidirectional layers of ballisticfibres to form said ballistic material.